Over the next funding period, this project will be concerned primarily with the synaptic organization of amacrine cells in the retina. Two projects are underway and one will be initiated shortly. 1. A light and electron microscopic analysis of the synaptic organization of the glycine-accumulating amacrine cells of the rabbit and mudpuppy retinas. 2. An electron microscopic analysis of glutamic acid dehydrogenase (GAD) containing amacrine cells in the rabbit retina. 3. A light and electron microscopic study of amacrine neurons containing certain peptides such as substance P, somatostatin, and enkephalin.